Twin cities suspend plans for cloud-seeding

Authorities cite lack of permission, failure to meet requirements for artificial rainfall

RAWALPINDI:

Authorities have suspended cloud-seeding-led artificial rainfall to counter toxic smog in the twin cities of Rawalpindi and Islamabad after technical glitches.

The authority responsible for cloud seeding didn't grant permission, nor did clouds form in Rawalpindi were found suitable for cloud seeding.

After a refusal by the aviation and meteorological department, the environmental protection department (EPD) and the Punjab government reversed the decision to make artificial rain in the twin cities.

Artificial rain is produced by the cloud seeding technique. For this, sodium chloride, silver iodide and other chemicals are sprayed on the clouds from a height of two to four thousand feet by special aircraft which form ice crystals in the clouds and make the clouds heavier. After the process, it starts raining. Land-based rockets or special devices can also be used instead of aircraft.

Artificial rain does not fall from all types of clouds and in all seasons; it requires a special environment. According to experts, artificial rain can be experienced using three out of ten types of clouds.

Clouds having layers 7,000 to 10,000 feet thick are suitable for artificial rain. It's also necessary that the humidity in the air is 70 to 75% and the wind speed is 30 to 50 km per hour.

The twin cities do have clouds but these don't fulfil the requirements and conditions of cloud seeding and the competent authority didn't agree.

Sources in the EPD confirmed that if the clouds and accessories are met according to the requirements, artificial rain could be decided later. This rain can be managed in any area or district from Rawalpindi to Lahore.

The cost of artificial rainfall by this method could be as high as Rs250 to Rs300 million, they added.